Amplifying system



Feb. 13, 1934. L, c

AMPLIFYING SYSTEM Filed April 16, 1932 7 a m. ML m ATTORNEY vision of anamplifier comprising two portions in to those skilled in the art uponreading this speciupon. There are a great many other crystalline moveswhen an electrical potential is impressed like materials the potentialgenerated is substan- Proceedings of the Institute of Radio Engineers",

Patented Feb. 13, 1934 1,947,049

UNITED STATES PATENT OFFICE 1,947,049 AMPLIFYING SYSTEM Earl L. Koch,Chicago, Ill., assignor, by mesne assignmen to Earl L. Koch HoldingCorporation, New York, N. Y., a corporation of New York ApplicationApril 16, 1932. Serial No. 605,647 3 Claims. (Cl. 179-171) amplifiers.

A further object of the invention is the proplifier embodying one formor" the invention.

attached to the outside of the crystal 11.

which there is no electrical connection between the output of oneportion and the input of the other portion.

Other objects and advantages will be apparent wire 17.

fication and the appended claims. able pp Piezo-electric crystalscomposed of quartz are well known in the art and it is known that theyrespond to electrical impulses impressed theresubstanoes which haveproperties similar to the quartz crystals in varying degree. The term"piezo-electric crystal as used herein may apply to any crystallinesubstance which responds or 20 as shown by the arrow 21.

thereon.

These crystals also have the property in that when flexed or distortedmechanically they generate a potential. It has been found that withtially the same although the crystals may be of different physicaldimensions, and the potential generated is also proportional to theamount of distortion or fiexure of the crystal. An article in support.

November 1931, entitled The Use of Rochelle Salt suitable manner-Crystals for Electrical Reproducers and Microphones by Sawyer, (pages2020-2029), describes these crystals.

This invention includes the use of a crystal, op-

erated by a suitable output circuit such as from one or more stages ofan amplifier, for mechanically flexing or driving a second, andpreferably smaller, crystal and impressing the voltage generated by thissecond crystal upon the input circuit of one or more succeeding stagesof amplification.

Referring to the drawing: Figure 1 is a view showing a driving crystaland a driven crystal and one method of mechanically transmitting motionfrom the former to the latter:

Figure 2 is an enlarged view of the driven crystal; and

dicated by the arrow 30.

gram in Figure 2.

amplify.

impressed thereon.

Figure 3 is a simple circuit diagram of an am- A twin crystal designatedgenerally by the numeral 10 consists of two crystals 11, 12 cementedtogether with a sheet of metai foil therebetween. A connection to thisfoil is shown at 13. A sheet of foil 14 is secured to the outsidesurface of the crystal 12 and a like sheet of foil (not shown) isConnections to these ioils are shown at 15 and 16 respectively and theseare combined into one lead One end of the combined crystal 10 is clampedinto a suitable mounting bracket 18 by means of which the crystal may berigidly secured to a suit- T'he other end of the crystal 10 has a clampmember 19 secured thereto having an extended arm 20 associatedtherewith. When a modulated potential is impressed upon the foil platesof the crystal 10 via the wires 13 and 1'? the end of the crystalcarrying the member 19 moves the arm A single crystal 22, preferably ofsmaller dimension and thickness has a foil plate 23 secured to one sidethereof and a second foil plate (not shown) on the other side thereofand lead wires 25 and 26 respectively connect to the foil plates.

One end of the crystal 22 is clamped into a suitable mounting bracket 27by means of which the crystal may be rigidly secured to a suitable Theother end of the crystal 22 has a clamp member 28 secured theretocarrying a stud 29, which is secured to the extended arm 20 in any Whena modulated potential is supplied to the crystal 10 as above describedand the arm 20 is thereby moved as shown by the arrow 21 this arm drivesor flexes the crystal, the motion being in- This causes a potential tobe generated by the crystal 22 in timed relation to the flexure thereofand this potential is fed to the input of one or more stages of theamplifier as shown in the dia- The input terminals 31 may be connectedto the detector circuit of a radio frequency amplifier or any source ofimpulses which it is desired to These impulses are amplified by thestage 32 and the output therefrom is impressed upon the crystal 10 viathe wires 13 and 17, causing the crystal to flex in timed relation tothe impulses 1 The extended arm 20, which is of long leverage giving anincreased motion at the end thereof, via the stud 29 drives or flexesthe crystal 22 in timed relation to the movement of the crystal 10 butat greater amplitude (due to the multiplication provided by the lengthof the arm 20) and impulses of a greater potential are generated by thecrystal 22 than is furnished to the crystal 10.

The output of the crystal 22 is impressed via the wires 25 and 26 uponthe input of a stage of amplification 33, wherein the voltage gainafforded by the combination of the crystals is further amplified.

The output of the stage 33 may be connected to a loud speaker 34, whichmay consist of a crystal similar to the crystal 10 with the exceptionthat the arm 20 is arranged to drive a suitable diaphragm.

The two crystals linked together comprise a converter adapted to receiveand be driven by impulses from one stage of an amplifier and to generateimpulses of similar character to, but higher potentials than, thosereceived. These generated impulses are delivered to a succeeding stageand a gain is effected.

Although a simple embodiment of this invention has been shown anddescribed, many changes and modifications may be made without departingfrom the scope of the appended claims.

What is claimed is:

1. In an amplifier in combination, an electronic device having a crystalconnected to the output circuit thereof, a second electronic devicehaving a crystal connected to the input circuit thereof, said crystalseach having one end secured to a rigid support and each opposite endmovable, each of said crystals having a fiat rectangular formation withfiat sides coated with metal foil forming terminals for the crystalswhereby the same are connected in the circuits aforesaid and meansconnecting the movable ends of said crystals.

2. In combination, a rectangular piezo-electric crystal having metalplates secured to the side surfaces thereof, and constituting terminalstherefor, a fixed support for said crystal whereby a portion thereof isleft free to vibrate, a lever connected to the free vibratory portion ofsaid crystal, a circuit containing a source of current impulses,connections between said plates and said circuit, a second rectangularpiezo-electric crystal having metal plates secured to the side surfacesthereof constituting terminals therefor, a fixed support for said lastcrystal whereby a portion thereof is left free to vibrate, a secondcircuit, connections between said last plates and said last circuit, andmechanical means connecting the free vibratory part of said last crystalto said lever whereby vibrations of said first crystal will betransmitted to said last crystal.

3. In combination, a circuit having an input end connected to a sourceof electrical impulses, means in said circuit for amplifying saidimpulses, a piezo-electric crystal having fiat sides, metal platessecured to the flat sides of said crys tal, circuit connections betweensaid plates and the output circuit of said amplifying means, a supportfor said crystal adapted to rigidly support the same while leaving aportion thereof free to vibrate, a lever connected to the free vibratoryportion of said crystal, a second crystal having a portion held againstvibration and portion free to vibrate, a connection between said leverand the free vibratory portion of said last crystal and means foramplifying the electrical impulses generated by said last crystal.

EARL L. KOCH.

